Quicker adding of new folders, plus bug fixes.

1) Quicker adding of new folders/contexts/goals. This isn't quite the "on-the-fly" creation that some people have been asking for (we still intend to make that in the future), but it is an improvement. Example: On the folder view, there is an "add folder..." link to the right of your tabs (if there is room). This link will now popup a form to quickly add a new folder without leaving the page. If there isn't room for the "add folder" link, it will be placed at the bottom of the "More Folders" popup box. Same goes for contexts and goals.

2) Fixed a bug where swapping tabs on the saved search page would sometimes not apply the search correctly to indented subtasks.
3) Fixed a bug where an apostrophe in a tag would cause that tag's tab to not load correctly.
4) Fixed a bug where the quick-dates on the calendar popup would display the wrong date on the second page reload of the "add multiple tasks" page.